Evaluation of Titanate Nanotubes (TiNTs) as a Modifier for the Determination of Lead (II) by Differential Pulse Adsorptive Stripping Voltammetry (DPAdSV)

Abstract

This work reports the synthesis and characterization of titanate nanotubes (TiNTs) and their use for the construction of an electrochemical sensor for lead (II) determination in water samples. TiNTs were prepared from TiO₂ by a hydrothermal route at 150 °C for 24 h in alkaline conditions. X-ray diffraction (XRD) measurements show peak enlargement and the presence of trititanate with different spaces between layers confirming the production of TiNTs of nanometric dimensions. In addition, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images demonstrated the presence of dispersed, homogenous, and nanometric tubular structure. TiNTs were used for the modification of carbon paste electrodes and evaluated for determination of lead (II) by differential pulse adsorptive stripping voltammetry (DPAdSV). Using the optimized conditions, the developed method provided a linear dynamic range (LDR) from 0.77 to 7.71 µM and limits of detection and quantification of 0.23 and 0.77 µM, respectively. Studies of addition and recovery in spiked water sample were performed, obtaining a recovery of 104.6%. A repeatability study resulted in a relative standard deviation of 11% for consecutive measurements. Using the same electrode, a reproducibility study provided a relative standard deviation of 3.9%.

KEYWORDS:

• Differential pulse adsorptive stripping voltammetry (DPAdSV)
• electrochemical sensor
• Lead (II)
• preconcentration
• titanate nanotube modified carbon paste electrode